FPR/Fuel Injectors

[nirvana19]

Two questions related to the fuel system, the first is are there any tips on changing out the fuel injectors/not spilling fuel anywhere, would anyone recommend unplugging the fuel pump relay with engine running to burn the excess fuel in the system, or is that unnecessary. I fly out Sunday and am quite busy until then, I can't stand looking at the rebuilt injectors sitting on my desk, how much time should I set aside for the job?

Second, the vacuum hose to my FPR has basically broken and I was inadvertently running with it completely disconnected for a while. I just put in a new FPR and am waiting on the vacuum hose, it's currently electrical taped on there but... my engine ran perfectly fine with the vacuum hose disconnected. Is this normal, should I expect a better running engine when I put the new hose on?

[Rus]

Unplugging the fuel pump relay while the engine is running is an effective way of minimizing the fuel pressure in the system. You will spill some fuel no matter how hard you try to avoid it. When I changed my injectors, it took me about two hours. Take your time on the fuel injector electrical connectors. They may be tough to remove. I popped the cover off of the fuel injector harness housing and then removed the injector connectors. When reconnecting, having the top cover off will allow you to seat the connectors firmly on the injectors. Also, don't forget to give the area around the fuel injectors a quick blast of carb cleaner or compressed air to remove any loose debris.

Your engine will run better when you replace the vacuum line. With that broken line, you have a vacuum leak. Check your other vacuum lines for cracks and tears too.

HTH

[whiskychaser]

With the vacuum hose off the FPR will be giving you more pressure than you really need. So your fuel consumption may improve a small amount

[e34.535i.sport]

I'm banging my refurbed design II's in tomorrow and gonna do a step by step if you can wait... I'll prob do the write up tomorrow night sometime (although there's a link to one on here already somewhere)- I can't wait to get them in! I know I'll be depressurising the system by removing the pump fuse to avoid unecessary mess!

I'm excited... :D :D :D

[gale]

There will be gas leakage, just wrap a rag around whichever connection you take apart & expect more when you take the fuel rail off. If you let it sit overnight without running, most/all of the pressure will have bled off. Likewise, it will idle like heck when started when finished, It will take a little while to smooth out until all the air is purged from the system. Here's some more info:

http://www.nmia.com/~dgnrg/page_17.htm

[whiskychaser]

I'm banging my refurbed design II's in tomorrow and gonna do a step by step if you can wait... I'll prob do the write up tomorrow night sometime (although there's a link to one on here already somewhere)- I can't wait to get them in! I know I'll be depressurising the system by removing the pump fuse to avoid unecessary mess!

I'm excited... :D :D :D
http://www.realoem.com/bmw/showparts.do?model=HD12&mospid=47382&btnr=13_0232&hg=13&fg=15
Watch the clips (no 5) dont ping off and drop down a grid:D. You might find the seals come out of the rails with the old injectors. They should push back in but if one splits and you are stuck I've got some nice new ones:)

[nirvana19]

I'm banging my refurbed design II's in tomorrow and gonna do a step by step if you can wait... I'll prob do the write up tomorrow night sometime (although there's a link to one on here already somewhere)- I can't wait to get them in! I know I'll be depressurising the system by removing the pump fuse to avoid unecessary mess!

I'm excited... :D :D :D

Those are the same ones I got, you got them off ebay as well iirc? I think I might give it a go this evening if time permits!

[e34.535i.sport]

http://www.realoem.com/bmw/showparts.do?model=HD12&mospid=47382&btnr=13_0232&hg=13&fg=15
Watch the clips (no 5) dont ping off and drop down a grid:D. You might find the seals come out of the rails with the old injectors. They should push back in but if one splits and you are stuck I've got some nice new ones:)

Thanks for the heads up! :D I'll take my time and hopefully won't break anything... It'll make a change.

Expect a call around midday for the new seals... ... :)

[e34.535i.sport]

Those are the same ones I got, you got them off ebay as well iirc? I think I might give it a go this evening if time permits!

Yeah, paid the equivalent of < £60... Ha ha, if you beat me to it let me know how it goes! :D

[Rus]

Whenever you replace the injectors, do yourself a favor and change those o-rings/seals as well. They should not be pushed into the rail as far as I can tell. I installed my o-rings on the injectors and then inserted them into the manifold and the fuel rail. In fact, I believe the new injectors ship with the o-rings already in place in their grooves. So, in summary, save yourself the headache and use new o-rings. No reason to do the job twice.

[e34.535i.sport]

Whenever you replace the injectors, do yourself a favor and change those o-rings/seals as well. They should not be pushed into the rail as far as I can tell. I installed my o-rings on the injectors and then inserted them into the manifold and the fuel rail. In fact, I believe the new injectors ship with the o-rings already in place in their grooves. So, in summary, save yourself the headache and use new o-rings. No reason to do the job twice.

Mine have been refurb'd and have new O-rings so that's looking good... Seems like Nirvana and I are in the same boat! However I didn't buy new seals and wonder if these will be ok to reuse? Hmmm...

A further question if anybody knows - Should I/we disconnect the battery to reset the ecu after changing the injectors?

[Rus]

Mine have been refurb'd and have new O-rings so that's looking good... Seems like Nirvana and I are in the same boat! However I didn't buy new seals and wonder if these will be ok to reuse? Hmmm...

A further question if anybody knows - Should I/we disconnect the battery to reset the ecu after changing the injectors?

Could you elaborate on these seals you speak of? There is only one type of seal on the fuel rail and the injectors - the o-rings. There are 2 per injector and one for the FPR...so a total of 13 o-rings. If your refurbished injectors have the o-rings, you're golden.

[e34.535i.sport]

Could you elaborate on these seals you speak of? There is only one type of seal on the fuel rail and the injectors - the o-rings. There are 2 per injector and one for the FPR...so a total of 13 o-rings. If your refurbished injectors have the o-rings, you're golden.

Hey Rus, apologies - I misread your post thinking you meant there were other seals as well as the o-ring (rubber washers in my imagination :p) but I'm with it now!

The new injectors had new o-rings so I was all good - Got them in (took about 4/5 hours!) any made up with the results!

Unfrotunately forgot to take the cameral out and by the time I realised it was way to late to start documenting... Hit a couple of snags which i'll try to outline in my injector thread if I can find it!